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linux/drivers/iio/magnetometer/ak8974.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Driver for the Asahi Kasei EMD Corporation AK8974
* and Aichi Steel AMI305 magnetometer chips.
* Based on a patch from Samu Onkalo and the AK8975 IIO driver.
*
* Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
* Copyright (c) 2010 NVIDIA Corporation.
* Copyright (C) 2016 Linaro Ltd.
*
* Author: Samu Onkalo <samu.p.onkalo@nokia.com>
* Author: Linus Walleij <linus.walleij@linaro.org>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/irq.h> /* For irq_get_irq_data() */
#include <linux/completion.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/bitops.h>
#include <linux/random.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/pm_runtime.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
/*
* 16-bit registers are little-endian. LSB is at the address defined below
* and MSB is at the next higher address.
*/
/* These registers are common for AK8974 and AMI30x */
#define AK8974_SELFTEST 0x0C
#define AK8974_SELFTEST_IDLE 0x55
#define AK8974_SELFTEST_OK 0xAA
#define AK8974_INFO 0x0D
#define AK8974_WHOAMI 0x0F
#define AK8974_WHOAMI_VALUE_AMI306 0x46
#define AK8974_WHOAMI_VALUE_AMI305 0x47
#define AK8974_WHOAMI_VALUE_AK8974 0x48
#define AK8974_WHOAMI_VALUE_HSCDTD008A 0x49
#define AK8974_DATA_X 0x10
#define AK8974_DATA_Y 0x12
#define AK8974_DATA_Z 0x14
#define AK8974_INT_SRC 0x16
#define AK8974_STATUS 0x18
#define AK8974_INT_CLEAR 0x1A
#define AK8974_CTRL1 0x1B
#define AK8974_CTRL2 0x1C
#define AK8974_CTRL3 0x1D
#define AK8974_INT_CTRL 0x1E
#define AK8974_INT_THRES 0x26 /* Absolute any axis value threshold */
#define AK8974_PRESET 0x30
/* AK8974-specific offsets */
#define AK8974_OFFSET_X 0x20
#define AK8974_OFFSET_Y 0x22
#define AK8974_OFFSET_Z 0x24
/* AMI305-specific offsets */
#define AMI305_OFFSET_X 0x6C
#define AMI305_OFFSET_Y 0x72
#define AMI305_OFFSET_Z 0x78
/* Different temperature registers */
#define AK8974_TEMP 0x31
#define AMI305_TEMP 0x60
/* AMI306-specific control register */
#define AMI306_CTRL4 0x5C
/* AMI306 factory calibration data */
/* fine axis sensitivity */
#define AMI306_FINEOUTPUT_X 0x90
#define AMI306_FINEOUTPUT_Y 0x92
#define AMI306_FINEOUTPUT_Z 0x94
/* axis sensitivity */
#define AMI306_SENS_X 0x96
#define AMI306_SENS_Y 0x98
#define AMI306_SENS_Z 0x9A
/* axis cross-interference */
#define AMI306_GAIN_PARA_XZ 0x9C
#define AMI306_GAIN_PARA_XY 0x9D
#define AMI306_GAIN_PARA_YZ 0x9E
#define AMI306_GAIN_PARA_YX 0x9F
#define AMI306_GAIN_PARA_ZY 0xA0
#define AMI306_GAIN_PARA_ZX 0xA1
/* offset at ZERO magnetic field */
#define AMI306_OFFZERO_X 0xF8
#define AMI306_OFFZERO_Y 0xFA
#define AMI306_OFFZERO_Z 0xFC
#define AK8974_INT_X_HIGH BIT(7) /* Axis over +threshold */
#define AK8974_INT_Y_HIGH BIT(6)
#define AK8974_INT_Z_HIGH BIT(5)
#define AK8974_INT_X_LOW BIT(4) /* Axis below -threshold */
#define AK8974_INT_Y_LOW BIT(3)
#define AK8974_INT_Z_LOW BIT(2)
#define AK8974_INT_RANGE BIT(1) /* Range overflow (any axis) */
#define AK8974_STATUS_DRDY BIT(6) /* Data ready */
#define AK8974_STATUS_OVERRUN BIT(5) /* Data overrun */
#define AK8974_STATUS_INT BIT(4) /* Interrupt occurred */
#define AK8974_CTRL1_POWER BIT(7) /* 0 = standby; 1 = active */
#define AK8974_CTRL1_RATE BIT(4) /* 0 = 10 Hz; 1 = 20 Hz */
#define AK8974_CTRL1_FORCE_EN BIT(1) /* 0 = normal; 1 = force */
#define AK8974_CTRL1_MODE2 BIT(0) /* 0 */
#define AK8974_CTRL2_INT_EN BIT(4) /* 1 = enable interrupts */
#define AK8974_CTRL2_DRDY_EN BIT(3) /* 1 = enable data ready signal */
#define AK8974_CTRL2_DRDY_POL BIT(2) /* 1 = data ready active high */
#define AK8974_CTRL2_RESDEF (AK8974_CTRL2_DRDY_POL)
#define AK8974_CTRL3_RESET BIT(7) /* Software reset */
#define AK8974_CTRL3_FORCE BIT(6) /* Start forced measurement */
#define AK8974_CTRL3_SELFTEST BIT(4) /* Set selftest register */
#define AK8974_CTRL3_RESDEF 0x00
#define AK8974_INT_CTRL_XEN BIT(7) /* Enable interrupt for this axis */
#define AK8974_INT_CTRL_YEN BIT(6)
#define AK8974_INT_CTRL_ZEN BIT(5)
#define AK8974_INT_CTRL_XYZEN (BIT(7)|BIT(6)|BIT(5))
#define AK8974_INT_CTRL_POL BIT(3) /* 0 = active low; 1 = active high */
#define AK8974_INT_CTRL_PULSE BIT(1) /* 0 = latched; 1 = pulse (50 usec) */
#define AK8974_INT_CTRL_RESDEF (AK8974_INT_CTRL_XYZEN | AK8974_INT_CTRL_POL)
/* HSCDTD008A-specific control register */
#define HSCDTD008A_CTRL4 0x1E
#define HSCDTD008A_CTRL4_MMD BIT(7) /* must be set to 1 */
#define HSCDTD008A_CTRL4_RANGE BIT(4) /* 0 = 14-bit output; 1 = 15-bit output */
#define HSCDTD008A_CTRL4_RESDEF (HSCDTD008A_CTRL4_MMD | HSCDTD008A_CTRL4_RANGE)
/* The AMI305 has elaborate FW version and serial number registers */
#define AMI305_VER 0xE8
#define AMI305_SN 0xEA
#define AK8974_MAX_RANGE 2048
#define AK8974_POWERON_DELAY 50
#define AK8974_ACTIVATE_DELAY 1
#define AK8974_SELFTEST_DELAY 1
/*
* Set the autosuspend to two orders of magnitude larger than the poweron
* delay to make sane reasonable power tradeoff savings (5 seconds in
* this case).
*/
#define AK8974_AUTOSUSPEND_DELAY 5000
#define AK8974_MEASTIME 3
#define AK8974_PWR_ON 1
#define AK8974_PWR_OFF 0
/**
* struct ak8974 - state container for the AK8974 driver
* @i2c: parent I2C client
* @orientation: mounting matrix, flipped axis etc
* @map: regmap to access the AK8974 registers over I2C
* @regs: the avdd and dvdd power regulators
* @name: the name of the part
* @variant: the whoami ID value (for selecting code paths)
* @lock: locks the magnetometer for exclusive use during a measurement
* @drdy_irq: uses the DRDY IRQ line
* @drdy_complete: completion for DRDY
* @drdy_active_low: the DRDY IRQ is active low
*/
struct ak8974 {
struct i2c_client *i2c;
struct iio_mount_matrix orientation;
struct regmap *map;
struct regulator_bulk_data regs[2];
const char *name;
u8 variant;
struct mutex lock;
bool drdy_irq;
struct completion drdy_complete;
bool drdy_active_low;
};
static const char ak8974_reg_avdd[] = "avdd";
static const char ak8974_reg_dvdd[] = "dvdd";
static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val)
{
int ret;
__le16 bulk;
ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2);
if (ret)
return ret;
*val = le16_to_cpu(bulk);
return 0;
}
static int ak8974_set_u16_val(struct ak8974 *ak8974, u8 reg, u16 val)
{
__le16 bulk = cpu_to_le16(val);
return regmap_bulk_write(ak8974->map, reg, &bulk, 2);
}
static int ak8974_set_power(struct ak8974 *ak8974, bool mode)
{
int ret;
u8 val;
val = mode ? AK8974_CTRL1_POWER : 0;
val |= AK8974_CTRL1_FORCE_EN;
ret = regmap_write(ak8974->map, AK8974_CTRL1, val);
if (ret < 0)
return ret;
if (mode)
msleep(AK8974_ACTIVATE_DELAY);
return 0;
}
static int ak8974_reset(struct ak8974 *ak8974)
{
int ret;
/* Power on to get register access. Sets CTRL1 reg to reset state */
ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
if (ret)
return ret;
ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF);
if (ret)
return ret;
ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF);
if (ret)
return ret;
if (ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A) {
ret = regmap_write(ak8974->map, AK8974_INT_CTRL,
AK8974_INT_CTRL_RESDEF);
if (ret)
return ret;
} else {
ret = regmap_write(ak8974->map, HSCDTD008A_CTRL4,
HSCDTD008A_CTRL4_RESDEF);
if (ret)
return ret;
}
/* After reset, power off is default state */
return ak8974_set_power(ak8974, AK8974_PWR_OFF);
}
static int ak8974_configure(struct ak8974 *ak8974)
{
int ret;
ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN |
AK8974_CTRL2_INT_EN);
if (ret)
return ret;
ret = regmap_write(ak8974->map, AK8974_CTRL3, 0);
if (ret)
return ret;
if (ak8974->variant == AK8974_WHOAMI_VALUE_AMI306) {
/* magic from datasheet: set high-speed measurement mode */
ret = ak8974_set_u16_val(ak8974, AMI306_CTRL4, 0xA07E);
if (ret)
return ret;
}
if (ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A)
return 0;
ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL);
if (ret)
return ret;
return regmap_write(ak8974->map, AK8974_PRESET, 0);
}
static int ak8974_trigmeas(struct ak8974 *ak8974)
{
unsigned int clear;
u8 mask;
u8 val;
int ret;
/* Clear any previous measurement overflow status */
ret = regmap_read(ak8974->map, AK8974_INT_CLEAR, &clear);
if (ret)
return ret;
/* If we have a DRDY IRQ line, use it */
if (ak8974->drdy_irq) {
mask = AK8974_CTRL2_INT_EN |
AK8974_CTRL2_DRDY_EN |
AK8974_CTRL2_DRDY_POL;
val = AK8974_CTRL2_DRDY_EN;
if (!ak8974->drdy_active_low)
val |= AK8974_CTRL2_DRDY_POL;
init_completion(&ak8974->drdy_complete);
ret = regmap_update_bits(ak8974->map, AK8974_CTRL2,
mask, val);
if (ret)
return ret;
}
/* Force a measurement */
return regmap_update_bits(ak8974->map,
AK8974_CTRL3,
AK8974_CTRL3_FORCE,
AK8974_CTRL3_FORCE);
}
static int ak8974_await_drdy(struct ak8974 *ak8974)
{
int timeout = 2;
unsigned int val;
int ret;
if (ak8974->drdy_irq) {
ret = wait_for_completion_timeout(&ak8974->drdy_complete,
1 + msecs_to_jiffies(1000));
if (!ret) {
dev_err(&ak8974->i2c->dev,
"timeout waiting for DRDY IRQ\n");
return -ETIMEDOUT;
}
return 0;
}
/* Default delay-based poll loop */
do {
msleep(AK8974_MEASTIME);
ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
if (ret < 0)
return ret;
if (val & AK8974_STATUS_DRDY)
return 0;
} while (--timeout);
dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n");
return -ETIMEDOUT;
}
static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result)
{
unsigned int src;
int ret;
ret = ak8974_await_drdy(ak8974);
if (ret)
return ret;
ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src);
if (ret < 0)
return ret;
/* Out of range overflow! Strong magnet close? */
if (src & AK8974_INT_RANGE) {
dev_err(&ak8974->i2c->dev,
"range overflow in sensor\n");
return -ERANGE;
}
ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6);
if (ret)
return ret;
return ret;
}
static irqreturn_t ak8974_drdy_irq(int irq, void *d)
{
struct ak8974 *ak8974 = d;
if (!ak8974->drdy_irq)
return IRQ_NONE;
/* TODO: timestamp here to get good measurement stamps */
return IRQ_WAKE_THREAD;
}
static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d)
{
struct ak8974 *ak8974 = d;
unsigned int val;
int ret;
/* Check if this was a DRDY from us */
ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
if (ret < 0) {
dev_err(&ak8974->i2c->dev, "error reading DRDY status\n");
return IRQ_HANDLED;
}
if (val & AK8974_STATUS_DRDY) {
/* Yes this was our IRQ */
complete(&ak8974->drdy_complete);
return IRQ_HANDLED;
}
/* We may be on a shared IRQ, let the next client check */
return IRQ_NONE;
}
static int ak8974_selftest(struct ak8974 *ak8974)
{
struct device *dev = &ak8974->i2c->dev;
unsigned int val;
int ret;
ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
if (ret)
return ret;
if (val != AK8974_SELFTEST_IDLE) {
dev_err(dev, "selftest not idle before test\n");
return -EIO;
}
/* Trigger self-test */
ret = regmap_update_bits(ak8974->map,
AK8974_CTRL3,
AK8974_CTRL3_SELFTEST,
AK8974_CTRL3_SELFTEST);
if (ret) {
dev_err(dev, "could not write CTRL3\n");
return ret;
}
msleep(AK8974_SELFTEST_DELAY);
ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
if (ret)
return ret;
if (val != AK8974_SELFTEST_OK) {
dev_err(dev, "selftest result NOT OK (%02x)\n", val);
return -EIO;
}
ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
if (ret)
return ret;
if (val != AK8974_SELFTEST_IDLE) {
dev_err(dev, "selftest not idle after test (%02x)\n", val);
return -EIO;
}
dev_dbg(dev, "passed self-test\n");
return 0;
}
static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg,
__le16 *tab, size_t tab_size)
{
int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size);
if (ret) {
memset(tab, 0xFF, tab_size);
dev_warn(&ak8974->i2c->dev,
"can't read calibration data (regs %u..%zu): %d\n",
reg, reg + tab_size - 1, ret);
} else {
add_device_randomness(tab, tab_size);
}
}
static int ak8974_detect(struct ak8974 *ak8974)
{
unsigned int whoami;
const char *name;
int ret;
unsigned int fw;
u16 sn;
ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami);
if (ret)
return ret;
name = "ami305";
switch (whoami) {
case AK8974_WHOAMI_VALUE_AMI306:
name = "ami306";
/* fall-through */
case AK8974_WHOAMI_VALUE_AMI305:
ret = regmap_read(ak8974->map, AMI305_VER, &fw);
if (ret)
return ret;
fw &= 0x7f; /* only bits 0 thru 6 valid */
ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn);
if (ret)
return ret;
add_device_randomness(&sn, sizeof(sn));
dev_info(&ak8974->i2c->dev,
"detected %s, FW ver %02x, S/N: %04x\n",
name, fw, sn);
break;
case AK8974_WHOAMI_VALUE_AK8974:
name = "ak8974";
dev_info(&ak8974->i2c->dev, "detected AK8974\n");
break;
case AK8974_WHOAMI_VALUE_HSCDTD008A:
name = "hscdtd008a";
dev_info(&ak8974->i2c->dev, "detected hscdtd008a\n");
break;
default:
dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ",
whoami);
return -ENODEV;
}
ak8974->name = name;
ak8974->variant = whoami;
if (whoami == AK8974_WHOAMI_VALUE_AMI306) {
__le16 fab_data1[9], fab_data2[3];
int i;
ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X,
fab_data1, sizeof(fab_data1));
ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X,
fab_data2, sizeof(fab_data2));
for (i = 0; i < 3; ++i) {
static const char axis[3] = "XYZ";
static const char pgaxis[6] = "ZYZXYX";
unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F;
unsigned fine = le16_to_cpu(fab_data1[i]);
unsigned sens = le16_to_cpu(fab_data1[i + 3]);
unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]);
unsigned pgain2 = pgain1 >> 8;
pgain1 &= 0xFF;
dev_info(&ak8974->i2c->dev,
"factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n",
axis[i], offz, sens, fine, pgaxis[i * 2],
pgain1, pgaxis[i * 2 + 1], pgain2);
}
}
return 0;
}
static int ak8974_measure_channel(struct ak8974 *ak8974, unsigned long address,
int *val)
{
__le16 hw_values[3];
int ret;
pm_runtime_get_sync(&ak8974->i2c->dev);
mutex_lock(&ak8974->lock);
/*
* We read all axes and discard all but one, for optimized
* reading, use the triggered buffer.
*/
ret = ak8974_trigmeas(ak8974);
if (ret)
goto out_unlock;
ret = ak8974_getresult(ak8974, hw_values);
if (ret)
goto out_unlock;
/*
* This explicit cast to (s16) is necessary as the measurement
* is done in 2's complement with positive and negative values.
* The follwing assignment to *val will then convert the signed
* s16 value to a signed int value.
*/
*val = (s16)le16_to_cpu(hw_values[address]);
out_unlock:
mutex_unlock(&ak8974->lock);
pm_runtime_mark_last_busy(&ak8974->i2c->dev);
pm_runtime_put_autosuspend(&ak8974->i2c->dev);
return ret;
}
static int ak8974_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2,
long mask)
{
struct ak8974 *ak8974 = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (chan->address > 2) {
dev_err(&ak8974->i2c->dev, "faulty channel address\n");
return -EIO;
}
ret = ak8974_measure_channel(ak8974, chan->address, val);
if (ret)
return ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
switch (ak8974->variant) {
case AK8974_WHOAMI_VALUE_AMI306:
case AK8974_WHOAMI_VALUE_AMI305:
/*
* The datasheet for AMI305 and AMI306, page 6
* specifies the range of the sensor to be
* +/- 12 Gauss.
*/
*val = 12;
/*
* 12 bits are used, +/- 2^11
* [ -2048 .. 2047 ] (manual page 20)
* [ 0xf800 .. 0x07ff ]
*/
*val2 = 11;
return IIO_VAL_FRACTIONAL_LOG2;
case AK8974_WHOAMI_VALUE_HSCDTD008A:
/*
* The datasheet for HSCDTF008A, page 3 specifies the
* range of the sensor as +/- 2.4 mT per axis, which
* corresponds to +/- 2400 uT = +/- 24 Gauss.
*/
*val = 24;
/*
* 15 bits are used (set up in CTRL4), +/- 2^14
* [ -16384 .. 16383 ] (manual page 24)
* [ 0xc000 .. 0x3fff ]
*/
*val2 = 14;
return IIO_VAL_FRACTIONAL_LOG2;
default:
/* GUESSING +/- 12 Gauss */
*val = 12;
/* GUESSING 12 bits ADC +/- 2^11 */
*val2 = 11;
return IIO_VAL_FRACTIONAL_LOG2;
}
break;
default:
/* Unknown request */
break;
}
return -EINVAL;
}
static void ak8974_fill_buffer(struct iio_dev *indio_dev)
{
struct ak8974 *ak8974 = iio_priv(indio_dev);
int ret;
__le16 hw_values[8]; /* Three axes + 64bit padding */
pm_runtime_get_sync(&ak8974->i2c->dev);
mutex_lock(&ak8974->lock);
ret = ak8974_trigmeas(ak8974);
if (ret) {
dev_err(&ak8974->i2c->dev, "error triggering measure\n");
goto out_unlock;
}
ret = ak8974_getresult(ak8974, hw_values);
if (ret) {
dev_err(&ak8974->i2c->dev, "error getting measures\n");
goto out_unlock;
}
iio_push_to_buffers_with_timestamp(indio_dev, hw_values,
iio_get_time_ns(indio_dev));
out_unlock:
mutex_unlock(&ak8974->lock);
pm_runtime_mark_last_busy(&ak8974->i2c->dev);
pm_runtime_put_autosuspend(&ak8974->i2c->dev);
}
static irqreturn_t ak8974_handle_trigger(int irq, void *p)
{
const struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
ak8974_fill_buffer(indio_dev);
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static const struct iio_mount_matrix *
ak8974_get_mount_matrix(const struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
struct ak8974 *ak8974 = iio_priv(indio_dev);
return &ak8974->orientation;
}
static const struct iio_chan_spec_ext_info ak8974_ext_info[] = {
IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix),
{ },
};
#define AK8974_AXIS_CHANNEL(axis, index, bits) \
{ \
.type = IIO_MAGN, \
.modified = 1, \
.channel2 = IIO_MOD_##axis, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE), \
.ext_info = ak8974_ext_info, \
.address = index, \
.scan_index = index, \
.scan_type = { \
.sign = 's', \
.realbits = bits, \
.storagebits = 16, \
.endianness = IIO_LE \
}, \
}
/*
* We have no datasheet for the AK8974 but we guess that its
* ADC is 12 bits. The AMI305 and AMI306 certainly has 12bit
* ADC.
*/
static const struct iio_chan_spec ak8974_12_bits_channels[] = {
AK8974_AXIS_CHANNEL(X, 0, 12),
AK8974_AXIS_CHANNEL(Y, 1, 12),
AK8974_AXIS_CHANNEL(Z, 2, 12),
IIO_CHAN_SOFT_TIMESTAMP(3),
};
/*
* The HSCDTD008A has 15 bits resolution the way we set it up
* in CTRL4.
*/
static const struct iio_chan_spec ak8974_15_bits_channels[] = {
AK8974_AXIS_CHANNEL(X, 0, 15),
AK8974_AXIS_CHANNEL(Y, 1, 15),
AK8974_AXIS_CHANNEL(Z, 2, 15),
IIO_CHAN_SOFT_TIMESTAMP(3),
};
static const unsigned long ak8974_scan_masks[] = { 0x7, 0 };
static const struct iio_info ak8974_info = {
.read_raw = &ak8974_read_raw,
};
static bool ak8974_writeable_reg(struct device *dev, unsigned int reg)
{
struct i2c_client *i2c = to_i2c_client(dev);
struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
struct ak8974 *ak8974 = iio_priv(indio_dev);
switch (reg) {
case AK8974_CTRL1:
case AK8974_CTRL2:
case AK8974_CTRL3:
case AK8974_INT_CTRL:
case AK8974_INT_THRES:
case AK8974_INT_THRES + 1:
return true;
case AK8974_PRESET:
case AK8974_PRESET + 1:
return ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A;
case AK8974_OFFSET_X:
case AK8974_OFFSET_X + 1:
case AK8974_OFFSET_Y:
case AK8974_OFFSET_Y + 1:
case AK8974_OFFSET_Z:
case AK8974_OFFSET_Z + 1:
return ak8974->variant == AK8974_WHOAMI_VALUE_AK8974 ||
ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A;
case AMI305_OFFSET_X:
case AMI305_OFFSET_X + 1:
case AMI305_OFFSET_Y:
case AMI305_OFFSET_Y + 1:
case AMI305_OFFSET_Z:
case AMI305_OFFSET_Z + 1:
return ak8974->variant == AK8974_WHOAMI_VALUE_AMI305 ||
ak8974->variant == AK8974_WHOAMI_VALUE_AMI306;
case AMI306_CTRL4:
case AMI306_CTRL4 + 1:
return ak8974->variant == AK8974_WHOAMI_VALUE_AMI306;
default:
return false;
}
}
static bool ak8974_precious_reg(struct device *dev, unsigned int reg)
{
return reg == AK8974_INT_CLEAR;
}
static const struct regmap_config ak8974_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = 0xff,
.writeable_reg = ak8974_writeable_reg,
.precious_reg = ak8974_precious_reg,
};
static int ak8974_probe(struct i2c_client *i2c,
const struct i2c_device_id *id)
{
struct iio_dev *indio_dev;
struct ak8974 *ak8974;
unsigned long irq_trig;
int irq = i2c->irq;
int ret;
/* Register with IIO */
indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974));
if (indio_dev == NULL)
return -ENOMEM;
ak8974 = iio_priv(indio_dev);
i2c_set_clientdata(i2c, indio_dev);
ak8974->i2c = i2c;
mutex_init(&ak8974->lock);
ret = iio_read_mount_matrix(&i2c->dev, "mount-matrix",
&ak8974->orientation);
if (ret)
return ret;
ak8974->regs[0].supply = ak8974_reg_avdd;
ak8974->regs[1].supply = ak8974_reg_dvdd;
ret = devm_regulator_bulk_get(&i2c->dev,
ARRAY_SIZE(ak8974->regs),
ak8974->regs);
if (ret < 0) {
if (ret != -EPROBE_DEFER)
dev_err(&i2c->dev, "cannot get regulators: %d\n", ret);
else
dev_dbg(&i2c->dev,
"regulators unavailable, deferring probe\n");
return ret;
}
ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
if (ret < 0) {
dev_err(&i2c->dev, "cannot enable regulators\n");
return ret;
}
/* Take runtime PM online */
pm_runtime_get_noresume(&i2c->dev);
pm_runtime_set_active(&i2c->dev);
pm_runtime_enable(&i2c->dev);
ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config);
if (IS_ERR(ak8974->map)) {
dev_err(&i2c->dev, "failed to allocate register map\n");
return PTR_ERR(ak8974->map);
}
ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
if (ret) {
dev_err(&i2c->dev, "could not power on\n");
goto power_off;
}
ret = ak8974_detect(ak8974);
if (ret) {
dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n");
goto power_off;
}
ret = ak8974_selftest(ak8974);
if (ret)
dev_err(&i2c->dev, "selftest failed (continuing anyway)\n");
ret = ak8974_reset(ak8974);
if (ret) {
dev_err(&i2c->dev, "AK8974 reset failed\n");
goto power_off;
}
pm_runtime_set_autosuspend_delay(&i2c->dev,
AK8974_AUTOSUSPEND_DELAY);
pm_runtime_use_autosuspend(&i2c->dev);
pm_runtime_put(&i2c->dev);
indio_dev->dev.parent = &i2c->dev;
switch (ak8974->variant) {
case AK8974_WHOAMI_VALUE_AMI306:
case AK8974_WHOAMI_VALUE_AMI305:
indio_dev->channels = ak8974_12_bits_channels;
indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels);
break;
case AK8974_WHOAMI_VALUE_HSCDTD008A:
indio_dev->channels = ak8974_15_bits_channels;
indio_dev->num_channels = ARRAY_SIZE(ak8974_15_bits_channels);
break;
default:
indio_dev->channels = ak8974_12_bits_channels;
indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels);
break;
}
indio_dev->info = &ak8974_info;
indio_dev->available_scan_masks = ak8974_scan_masks;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->name = ak8974->name;
ret = iio_triggered_buffer_setup(indio_dev, NULL,
ak8974_handle_trigger,
NULL);
if (ret) {
dev_err(&i2c->dev, "triggered buffer setup failed\n");
goto disable_pm;
}
/* If we have a valid DRDY IRQ, make use of it */
if (irq > 0) {
irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq));
if (irq_trig == IRQF_TRIGGER_RISING) {
dev_info(&i2c->dev, "enable rising edge DRDY IRQ\n");
} else if (irq_trig == IRQF_TRIGGER_FALLING) {
ak8974->drdy_active_low = true;
dev_info(&i2c->dev, "enable falling edge DRDY IRQ\n");
} else {
irq_trig = IRQF_TRIGGER_RISING;
}
irq_trig |= IRQF_ONESHOT;
irq_trig |= IRQF_SHARED;
ret = devm_request_threaded_irq(&i2c->dev,
irq,
ak8974_drdy_irq,
ak8974_drdy_irq_thread,
irq_trig,
ak8974->name,
ak8974);
if (ret) {
dev_err(&i2c->dev, "unable to request DRDY IRQ "
"- proceeding without IRQ\n");
goto no_irq;
}
ak8974->drdy_irq = true;
}
no_irq:
ret = iio_device_register(indio_dev);
if (ret) {
dev_err(&i2c->dev, "device register failed\n");
goto cleanup_buffer;
}
return 0;
cleanup_buffer:
iio_triggered_buffer_cleanup(indio_dev);
disable_pm:
pm_runtime_put_noidle(&i2c->dev);
pm_runtime_disable(&i2c->dev);
ak8974_set_power(ak8974, AK8974_PWR_OFF);
power_off:
regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
return ret;
}
static int ak8974_remove(struct i2c_client *i2c)
{
struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
struct ak8974 *ak8974 = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
iio_triggered_buffer_cleanup(indio_dev);
pm_runtime_get_sync(&i2c->dev);
pm_runtime_put_noidle(&i2c->dev);
pm_runtime_disable(&i2c->dev);
ak8974_set_power(ak8974, AK8974_PWR_OFF);
regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
return 0;
}
static int __maybe_unused ak8974_runtime_suspend(struct device *dev)
{
struct ak8974 *ak8974 =
iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
ak8974_set_power(ak8974, AK8974_PWR_OFF);
regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
return 0;
}
static int __maybe_unused ak8974_runtime_resume(struct device *dev)
{
struct ak8974 *ak8974 =
iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
int ret;
ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
if (ret)
return ret;
msleep(AK8974_POWERON_DELAY);
ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
if (ret)
goto out_regulator_disable;
ret = ak8974_configure(ak8974);
if (ret)
goto out_disable_power;
return 0;
out_disable_power:
ak8974_set_power(ak8974, AK8974_PWR_OFF);
out_regulator_disable:
regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
return ret;
}
static const struct dev_pm_ops ak8974_dev_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
pm_runtime_force_resume)
SET_RUNTIME_PM_OPS(ak8974_runtime_suspend,
ak8974_runtime_resume, NULL)
};
static const struct i2c_device_id ak8974_id[] = {
{"ami305", 0 },
{"ami306", 0 },
{"ak8974", 0 },
{"hscdtd008a", 0 },
{}
};
MODULE_DEVICE_TABLE(i2c, ak8974_id);
static const struct of_device_id ak8974_of_match[] = {
{ .compatible = "asahi-kasei,ak8974", },
{ .compatible = "alps,hscdtd008a", },
{}
};
MODULE_DEVICE_TABLE(of, ak8974_of_match);
static struct i2c_driver ak8974_driver = {
.driver = {
.name = "ak8974",
.pm = &ak8974_dev_pm_ops,
.of_match_table = of_match_ptr(ak8974_of_match),
},
.probe = ak8974_probe,
.remove = ak8974_remove,
.id_table = ak8974_id,
};
module_i2c_driver(ak8974_driver);
MODULE_DESCRIPTION("AK8974 and AMI30x 3-axis magnetometer driver");
MODULE_AUTHOR("Samu Onkalo");
MODULE_AUTHOR("Linus Walleij");
MODULE_LICENSE("GPL v2");
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